mikalv / partially

Implementation of the paper "Provably Secure Partially Blind Signatures" by Masayuki ABE and Tatsuaki OKAMOTO.

Provably Secure Partially Blind Signatures

This is an implementation of the partially blind signature issuing protocol from the paper "Provably Secure Partially Blind Signatures" by Masayuki ABE and Tatsuaki OKAMOTO.

Here is a demo of the current usage.

L, N = 1024, 160
# Unblinded info the signer and user both agree on out of channel.
info = b'Time to live'
# Blinded part of the message
msg = b'A commodity takes on, like the added meaning invested in a fetishized object, the value of the labor that went into making it.'

params = choose_parameters(L, N)
signer = Signer(params)
signer.start(info)

user = User(params, signer.keypair.y) # y is the public key
user.start(info, msg)

a, b = signer.one()
e = user.two(a, b)
r, c, s, d = signer.three(e)
rho, omega, delta, sigma = user.four(r, c, s, d)

# check the signature
assert check(rho, omega, delta, sigma, user.z, msg, user.y, params)